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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: gangsta on April 19, 2006, 02:25:25 PM

Title: ph level
Post by: gangsta on April 19, 2006, 02:25:25 PM
Please, Please, Please someone help me I'm in a slump. What is the basic Ph level for nitrate at 20c or room temperature? I looked everywhere for the answere and I cant seem to find it. The teacher wont lend me a hand so I'm stuck.
Title: Re: ph level
Post by: Borek on April 19, 2006, 02:54:26 PM
Is nitric acid strong or weak?
Title: Re: ph level
Post by: spoudyal3 on April 24, 2006, 08:27:12 PM
Nitric acid (HNO3) is a strong acid. Just as a referece, these are all the acids, in no particular order (although HCl is the strongest acid), that are generally accepted as being "strong":

Good Luck!

-DaKid
Title: Re: ph level
Post by: AWK on April 25, 2006, 01:40:53 AM
Which nitrate: ammonium, potassium, magnesium one?
Title: Re: ph level
Post by: pantone159 on April 25, 2006, 02:14:32 AM
Quote from: DaKid on April 24, 2006, 08:27:12 PM
(although HCl is the strongest acid)

Actually, HCl is weaker than HBr which is weaker than HI.  (At least in water.)  All three are strong enough, however, that this doesn't really matter much.
Title: Re: ph level
Post by: Borek on April 25, 2006, 03:13:40 AM
Quote from: DaKid on April 24, 2006, 08:27:12 PM
Nitric acid (HNO3) is a strong acid. Just as a referece, these are all the acids, in no particular order (although HCl is the strongest acid), that are generally accepted as being "strong":

Of these listed HClO4 is the strongest. HNO3 - although strong - is relatively weak when compared to the rest. Still stronger than HSO4-
Title: Re: ph level
Post by: spoudyal3 on April 26, 2006, 12:52:23 AM
Whoa really guys? I always thought that HCl was the strongest stuff out there! Hmmm ... I need to talk to my chem teachers. Sorry, but I still can not find the answer to your question? We need a specific nitrate I think. Good luck.

-DaKid
Title: Re: ph level
Post by: AWK on April 26, 2006, 02:13:52 AM
Quote from: DaKid on April 26, 2006, 12:52:23 AM
Whoa really guys? I always thought that HCl was the strongest stuff out there! Hmmm ... I need to talk to my chem teachers. Sorry, but I still can not find the answer to your question? We need a specific nitrate I think. Good luck.

-DaKid
There are also stronger acids than HClO4, but outside the Borek list
Title: Re: ph level
Post by: spoudyal3 on April 27, 2006, 11:25:28 PM
Hmmm ... Borek list? Sorry, I am unfamiliar with this list. Never heard of it in my life (hope it is not the list I gave)! What exactly is it (other than a list of acids of course). Thanks.

-DaKid
Title: Re: ph level
Post by: mike on April 27, 2006, 11:29:21 PM
I don't think that the "Borek List" is an official chemistry term (maybe one day). I think they just mean the acids Borek was talking about.
Title: Re: ph level
Post by: spoudyal3 on April 27, 2006, 11:32:10 PM
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA ....HAHAHAHAHAHAHAHAHAHAHAHAHA...HAHAHAHAHAHAHAHAHAHAHAHAHA....HA! My bad. I get it now. How about we just let that one slide, okay guys?

-DaKid
Title: Re: ph level
Post by: Donaldson Tan on April 28, 2006, 09:41:39 PM
Nitric acid is a strong acid, so you can consider 100% dissociation to calculate its pH.

pH = -log10(concentration of HNO3)
Title: Re: ph level
Post by: Borek on April 29, 2006, 03:28:39 AM
pKa = -1

Strong, but much weaker than others.

For 1M solution difference is 0.04 pH unit.
Title: Re: ph level
Post by: rctrackstar2007 on May 05, 2006, 02:57:41 PM
Quote from: gangsta on April 19, 2006, 02:25:25 PM
Please, Please, Please someone help me I'm in a slump. What is the basic Ph level for nitrate at 20c or room temperature? I looked everywhere for the answere and I cant seem to find it. The teacher wont lend me a hand so I'm stuck.


To answer this, nitrate has no pH individually. For there to be a pH level there has to be a hydronium ion concentration and as any good chemist might have noticed, there are no H+ ions in NO3(2-). If you are looking for the pH of nitric acid that is completely different.
Title: Re: ph level
Post by: Borek on May 05, 2006, 03:22:20 PM
Quote from: rctrackstar2007 on May 05, 2006, 02:57:41 PM
To answer this, nitrate has no pH individually. For there to be a pH level there has to be a hydronium ion concentration and as any good chemist might have noticed, there are no H+ ions in NO3(2-). If you are looking for the pH of nitric acid that is completely different.

Have you heard about hydrolyzis? Bronsted-Lowry's acids and bases?

http://www.chembuddy,com/?left=pH-calculation&right=bronsted-lowry-theory
Title: Re: ph level
Post by: tennis freak on May 09, 2006, 09:28:54 PM
nitrate itself has no pH since it doesn't have an H+ or an OH- meaning that it can't be an acid or a base which means you can't measure the pH or the pOH
Title: Re: ph level
Post by: mike on May 09, 2006, 10:30:02 PM
H and OH are not the only things that can define an acid or base.
Title: Re: ph level
Post by: tennis freak on May 09, 2006, 10:31:38 PM
really what else defines an acid or a base then? i always thought is was the H and OH in the compound
Title: Re: ph level
Post by: rctrackstar2007 on May 09, 2006, 10:40:28 PM
Quote from: mike on May 09, 2006, 10:30:02 PM
H and OH are not the only things that can define an acid or base.

well i'm glad i've learned this now

i'll be checking out that site to figure out about it cuz i was under the impression that for a pH you had to have H+ ions and pOH you must have had OH- ions  :P
Title: Re: ph level
Post by: mike on May 09, 2006, 10:45:11 PM
Quote
really what else defines an acid or a base then? i always thought is was the H and OH in the compound

Well you can try looking up things like acid/base definitions: Bronsted-Lowry compared with Lewis, these are the main ones I use anyway.

Borek's website is also a good place to learn this type of thing (check out his signature)
Title: Re: ph level
Post by: Will on May 10, 2006, 12:47:06 PM
Quote from: AWK on April 25, 2006, 01:40:53 AM
Which nitrate: ammonium, potassium, magnesium one?

Exactly! It depends which nitrate salt gangsta was talking about.
Ammonium will be slightly more acidic than potassium salts for example.
Also, the pH depends how much salt you have and in how much water (ie concentration).